once

 
Pronunciation: /wʌns/

adverb

  • 1on one occasion or for one time only: they deliver once a week (as noun the once) informal he’d only met her the once
  • (usually with negative or if) on even one occasion; at all (used for emphasis): he never once complained if she once got an idea in her head you’d never move it
  • 2at some time in the past; formerly: Gran had once been a famous singer
  • 3multiplied by one: once two is two

conjunction

  • as soon as; when: once the grapes were pressed, the juice was put into barrels

Phrases

all at once

  • 1suddenly: all at once the noise stopped
  • 2all at the same time: a lot of beans are ready all at once

at once

  • 1immediately: I fell asleep at once
  • 2at the same time; simultaneously: computers that can do many things at once

for once (or this once)

on this occasion only, as an exception: I hope you’ll forgive me this once

once a ——, always a ——

proverb a person cannot change their fundamental nature: once a whinger, always a whinger

once again (or more)

one more time.

once and for all (or once for all)

now and for the last time; finally.

once and future

denoting someone or something that is eternal or enduring: side two contains four once and future hit singles
[ 1950s: from T. H. White's Once and Future King (1958)]

once bitten, twice shy

see bite.

once (or every once) in a while

from time to time; occasionally.

once or twice

a few times.

once upon a time

at some time in the past (used as a conventional opening of a story).
formerly: once upon a time she would have been jealous, but no longer

Origin:

Middle English ones, genitive of one. The spelling change in the 16th century was in order to retain the unvoiced sound of the final consonant